Dr. Alok Gupta

Research interest

I am primarily interested in how plants communicate with their pollinators and which floral signals or mechanisms are involved in such interactions. More specifically, I am always curious about the astonishing floral scent diversity found between flower sexes or among populations and their underlying scent biosynthetic pathways. In addition to my primary interests, I am now also addressing questions concerning how and why androdioecy evolves in plants.

Current Projects

Epigenetic regulation of sex expression and fitness in Fraxinus ornus
In recent years, much progress has been made in understanding the evolution of sexual dimorphisms in flowering plants. However, we are still lagging behind in attaining a clear overview about the genetic architecture and evolution of trait divergence between plant sexes. To understand these unresolved issues, I am focussing on the sexually dimorphic plant species, F. ornus. Although the species appears to be androdioecious, with males co-occurring with hermaphrodites, the observed 1:1 sex ratio points towards functional or cryptic dioecy in this species. To advance our knowledge of sexual dimorphism in F. ornus, I am using methyl-sensitive AFLP to analyze differential methylation patterns between male and female individuals of Fraxinus ornus.

Sexual dimorphism in scent emission and its underlying genetics in Fraxinus ornus
Plants usually display sexual dimorphism in morphology, physiology, and their life-history traits. There are also few striking examples, where male and female flowers even differ in floral scent emission in order to influence pollinator visitations. Although a large body of investigations has established that scent is an important signal for ensuring the reproductive success, nothing is known to date about the floral scent emission, its involvement in sexual dimorphism, and the reproductive ecology of insect pollinated Fraxinus species. Interestingly, F. ornus is pollinated by both insects and wind, and floral scent probably plays a key role in the maintenance of entomophilous pollination system. I am using gas chromatography-mass spectrometry (GC-MS) to analyze the scent volatiles from European natural populations, and next-generation sequencing for the identification of scent-related floral transcripts.

Previous Projects

During my PhD research at Zurich, I focused on Gymnadenia (Orchidaceae) and Silene (Caryophyllaceae) species. Both species release different types of volatile scent molecules in the large quantities and these volatile chemicals serve as a key trait for attracting different suits of pollinators. I functionally characterized several key fragrance-related genes and studied their evolutionary patterns. Surprisingly, only a few plant species have been explored for floral fragrance-based molecular studies. My doctoral thesis contributed to our understanding of the scent in two new plant systems and threw light on related pollinator-imposed selection.

Curriculum vitae

Nov 2006-August 2011:
Doctor of Sciences ETH Zurich, Switzerland
Thesis title: Identification, characterization, and evolutionary patterns of floral fragrance genes in Gymnadenia and Silene species
Advisors: Prof. Alex Widmer and Prof. Florian Schiestl

Sep 2011- Sep2012:
Post-Doctoral Scientist, Institute of Systematic Botany, University of Zurich, Switzerland (Advisor: Prof. Florian Schiestl)

Oct 2012- Present:
Post-Doctoral Scientist, University of Lausanne, Switzerland (Advisor: Prof. John Pannell)



Biophore - CH-1015 Lausanne
Tel. +41 21 692 41 60
Fax +41 21 692 41 65